First impressions can leave lasting images, and the initial judgments of Reggie McKenzie and Dennis Allen have been duly harsh. Hired to steer the Raiders into a new and modern era, the rookie bosses crashed in public.

The 2012 season left nasty scars on McKenzie, the general manager, and on Allen, the head coach. So now they’re eager to prove they’re not a couple of overmatched rubes.

“When things don’t go well, we’re all involved — coaches, players, management — everybody has a piece of it,” Allen, who finished his rookie season in Oakland with a 4-12 record, said recently.

“And when we have the success we’re going to have, everybody’s going to have a piece of it. Right now we’re building that.”

They’re arriving at dawn, walking into the team’s Harbor Bay facility with a purpose and walking out at dusk with a sense of accomplishment. The football side of the franchise is, they insist, better organized and equipped than it was a year ago. Gone, they say, is the chaos created when many new faces converge on a single new place.

“When you ask me what makes me feel better about the team, I have to say everything,” McKenzie said recently. “Everything I needed to do last year already is in better shape this year.

“We’re going to build this thing. We’re going to build it the right way.”

There is that word again. Build. That’s the attitude permeating team headquarters. As McKenzie and Allen arrive at the NFL Scouting Combine this week to inspect draft-eligible talent, holding the No. 3 overall pick, they wish they held something they don’t — at least not yet.

They’d like to have more draft picks. They still believe, quite firmly, that the draft is the surest way to build a team — and, in this instance, to make the Raiders matter again. McKenzie and Allen turn westward, across the bay, to cite a classic example.

“That’s how the 49ers were built,” Allen says. “Look at their offensive line. The left tackle was a first-round draft choice. Their left guard was a first-round draft choice. Their right tackle was a first-round draft choice. Their quarterback was a first-round draft choice, and then they went with a second-round draft choice. Michael Crabtree was a first-rounder. Their tight end was a first-round draft choice.”

McKenzie pointed to the draft’s impact on San Francisco’s defense, on which five starters — NaVorro Bowman, Dashon Goldson, Ray McDonald, Aldon Smith and Patrick Willis — were selected in the draft. Three others, Justin Smith, Carlos Rogers and Donte Whitner, were first-round choices of other teams before coming to the 49ers as free agents.

“They (inherited) a lot of talent,” McKenzie said of coach Jim Harbaugh and his staff, hired in 2011. “And the coaches came in knowing know what they are supposed to do. That’s how you build it. People can (criticize) the prior staffs and, yes, those staffs had some direction issues. But they still put together a talented team.”

This is where McKenzie comes to the aid of himself and, moreover, his head coach. It’s unfair, the GM said, to compare the immediate and dramatic improvement of the 49ers under Harbaugh in 2011 with Oakland’s regression in Allen’s first season because Harbaugh had the benefit of Pro Bowl talent and, moreover, staff continuity.

All three of Harbaugh’s coordinators came with him from Stanford, as did three more assistants. A couple more worked under Harbaugh at the University of San Diego. Offensive line coach Tim Drevno has been with Harbaugh since 2003 at USD.

The assembling of Allen’s staff last season was, by contrast, a fire drill. The result was a first-time head coach getting to know his assistants, while trying to read and react to McKenzie’s desires, while trying to cope with the demands of coaching the team.

There were times, Allen concedes, when the challenges took a toll.

“What I learned is you have to stand up, stand out in front and lead the team through (challenging circumstances),” he said. “I think at times I did a good job. At other times, when I look back, if I’m really honest, I say, ‘Damn, I could have done a better job here.’ The bottom line is you have to lead everybody.

“The area of improvement where I have to be better is working with the special teams and the defense, letting them know what my vision is and providing a framework. I know I’ll be better at providing clarity for the assistants.”

Allen and McKenzie realize they confront several layers of competition, beginning with the AFC West and the conference overall. There also is the local sports market, more specifically the other NFL franchise, which is riding a wave of success.

The 49ers are coming off a Super Bowl appearance, something the Raiders have done once since returning in 1995. San Francisco has surrounded its core of stars with young talent, while the Raiders are scouring the wires. The Niners are even building a new stadium, at warp speed, while the Raiders’ stadium ambitions remain in the dream stage.

“It really doesn’t affect what I do,” McKenzie said of San Francisco’s revival. “But it does provide some motivation, because you want to be good. You want to own your home.

“But everybody loves a winner. So I understand. It’s my job to bring a winner. And that’s what I expect to do. I’ll get my motivation anywhere I can get it.”

In illuminating the lessons of 2012 and how they might apply those lessons to 2013, McKenzie and Allen were about as candid as could be expected. They owned up to their mistakes, strongly implying they will not be repeated.

And while much of what they said struck me as fair and reasonable, if they’re coming off another dreadful season next February and still employed here and saying the same things, their words will sound hollow and breezy, like an oversized bag of excuses.

The post-game handshake between coaches Jack Del Rio of the Raiders and Andy Reid of the Chiefs eventually came off Thursday night, but it seemed for a while that there’s enough bad blood between the two that it might not happen. Once time ran out in the Chiefs’ 21-13 win that gave K.C. a leg up in the AFC West...